Method, manufacture, and apparatus for instantiating plugin from within browser

ABSTRACT

A method, apparatus, and manufacture for instantiating a browser plugin is provided. A client web browser of a client is employed to instantiate a browser plugin for the client web browser. Next, the client web browser is employed to obtain a reference to the browser plugin. Then, a command is given to the browser plugin via the reference to the browser plugin. The browser plugin is used by the client web browser rather than the web page.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a utility patent application based on previouslyfiled U.S. Provisional Patent Application Ser. No. 61/569,755 filed onDec. 12, 2011, the benefit of which is hereby claimed under 35 U.S.C.§119(e) and incorporated herein by reference.

TECHNICAL FIELD

The invention is related to computer software, and in particular, butnot exclusively, to a method, manufacture, and apparatus for using theweb browser, rather than the web page, to instantiate a browser pluginfor the web browser.

BACKGROUND

Today, HTML5 media tags, such as <video> and <audio> tags are availableto provide content providers with a simple way to deliver their audioand video content onto the web, and have it play on any web browser orbrowser-based device. The underlying functionality of the HTML mediatags are referred to as HTML media elements. The <video> and <audio>tags enable an ecosystem where plugins are no longer required to playthis content and end users have consistent access to it across theirweb-enabled devices. To date, content protection mechanisms to enableuse of content that its owner wants to protect from unauthorized use arenot supported in the context of HTML media tags.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention aredescribed with reference to the following drawings, in which:

FIG. 1 illustrates a system diagram of one embodiment of an environmentin which the embodiments of the invention may be practiced;

FIG. 2 shows one embodiment of a client device that may be included inthe system of FIG. 1;

FIG. 3 illustrates one embodiment of a network device that may beincluded in the system of FIG. 1;

FIG. 4 shows a flowchart of an embodiment of a process;

FIG. 5A illustrates a flowchart of an embodiment of a process that maybe employed as an embodiment of process of FIG. 4;

FIG. 5B illustrates a flowchart of an embodiment of a process that maybe employed as an embodiment of part of the process of FIG. 5A;

FIG. 6 shows a system that may be employed as an embodiment of thesystem of FIG. 1;

FIG. 7 illustrates a flowchart of an embodiment of the process of FIG. 4and/or FIG. 5A; and

FIG. 8 shows an embodiment of a web page and a browser implementation ofthe web page, in accordance with aspects of the invention.

DETAILED DESCRIPTION

Various embodiments of the present invention will be described in detailwith reference to the drawings, where like reference numerals representlike parts and assemblies throughout the several views. Reference tovarious embodiments does not limit the scope of the invention, which islimited only by the scope of the claims attached hereto. Additionally,any examples set forth in this specification are not intended to belimiting and merely set forth some of the many possible embodiments forthe claimed invention.

Throughout the specification and claims, the following terms take atleast the meanings explicitly associated herein, unless the contextdictates otherwise. The meanings identified below do not necessarilylimit the terms, but merely provide illustrative examples for the terms.The meaning of “a,” “an,” and “the” includes plural reference, and themeaning of “in” includes “in” and “on.” The phrase “in one embodiment,”as used herein does not necessarily refer to the same embodiment,although it may. Similarly, the phrase “in some embodiments,” as usedherein, when used multiple times, does not necessarily refer to the sameembodiments, although it may. As used herein, the term “or” is aninclusive “or” operator, and is equivalent to the term “and/or,” unlessthe context clearly dictates otherwise. The term “based, in part, on”,“based, at least in part, on”, or “based on” is not exclusive and allowsfor being based on additional factors not described, unless the contextclearly dictates otherwise. The term “coupled” means at least either adirect electrical connection between the items connected, or an indirectconnection through one or more passive or active intermediary devices.The term “signal” means at least one current, voltage, charge,temperature, data, or other signal.

Briefly stated, the invention is related to a method, apparatus, andmanufacture for instantiating a browser plugin. A client web browser ofa client is employed to instantiate a browser plugin for the client webbrowser. Next, the client web browser is employed to obtain a referenceto the browser plugin. Then, a command is given to the browser pluginvia the reference to the browser plugin.

Illustrative Operating Environment

FIG. 1 shows components of one embodiment of an environment in which theinvention may be practiced. Not all the components may be required topractice the invention, and variations in the arrangement and type ofthe components may be made without departing from the spirit or scope ofthe invention. As shown, system 100 of FIG. 1 includes local areanetworks (“LANs”) wide area networks (“WANs”)—(network) 111, wirelessnetwork 110, client devices 101-104, and server device 108.

One embodiment of client devices 101-104 is described in more detailbelow in conjunction with FIG. 2. Generally, however, client devices102-104 may include virtually any portable computing device capable ofreceiving and sending a message over a network, such as wireless network110, or the like. Client devices 102-104 may also be described generallyas client devices that are configured to be portable. Thus, clientdevices 102-104 may include virtually any portable computing devicecapable of connecting to another computing device and receivinginformation. Such devices include portable devices such as, cellulartelephones, smart phones, display pagers, radio frequency (RF) devices,infrared (IR) devices, Personal Digital Assistants (PDAs), handheldcomputers, laptop computers, wearable computers, tablet computers,integrated devices combining one or more of the preceding devices, andthe like. As such, client devices 102-104 typically range widely interms of capabilities and features. For example, a cell phone may have anumeric keypad and a few lines of monochrome LCD display on which onlytext may be displayed. In another example, a web-enabled mobile devicemay have a touch sensitive screen, a stylus, and several lines of colorLCD display in which both text and graphics may be displayed.

Client device 101 may include virtually any computing device capable ofcommunicating over a network to send and receive information. The set ofsuch devices may include devices that typically connect using a wired orwireless communications medium such as personal computers,multiprocessor systems, microprocessor-based or programmable consumerelectronics, network PCs, or the like. In one embodiment, at least someof client devices 102-104 may operate over wired and/or wirelessnetwork.

A web-enabled client device may include a browser application that isconfigured to receive and to send web pages, web-based messages, and thelike. The browser application may be configured to receive and displaygraphics, text, multimedia, and the like, employing virtually anyweb-based language, including a wireless application protocol messages(WAP), and the like. In one embodiment, the browser application isenabled to employ Handheld Device Markup Language (HDML), WirelessMarkup Language (WML), WMLScript, JavaScript, Standard GeneralizedMarkup Language (SMGL), HyperText Markup Language (HTML), eXtensibleMarkup Language (XML), and the like, to display and send a message. Inone embodiment, a user of the client device may employ the browserapplication to perform various activities over a network (online).However, another application may also be used to perform various onlineactivities.

Wireless network 110 is configured to couple client devices 102-104 andits components with network 111. Wireless network 110 contains at leastone Access Point (not shown in FIG. 1). Wireless network 110 may includeany of a variety of wireless sub-networks that may further overlaystand-alone ad-hoc networks, and the like. Such sub-networks may includemesh networks, Wireless LAN (WLAN) networks, cellular networks, and thelike.

Wireless network 110 may further include an autonomous system ofterminals, gateways, routers, and the like connected by wireless radiolinks, and the like. These connectors may be configured to move freelyand randomly and organize themselves arbitrarily, such that the topologyof wireless network 110 may change rapidly.

Wireless network 110 may further employ a plurality of accesstechnologies including 2^(nd) (2G), 3^(rd) (3G), 4^(th) (4G), 5^(th)(5G) generation radio access for cellular systems, WLAN, Wireless Router(WR) mesh, and the like. Access technologies such as 2G, 3G, 4G, andfuture access networks may enable wide area coverage for mobile devices,such as client devices 102-104 with various degrees of mobility. Forexample, wireless network 110 may enable a radio connection through aradio network access such as Global System for Mobil communication(GSM), General Packet Radio Services (GPRS), Enhanced Data GSMEnvironment (EDGE), Wideband Code Division Multiple Access (WCDMA), andthe like.

Network 111 is configured to couple network devices with other computingdevices, and through wireless network 110 to client devices 102-104.Network 111 is enabled to employ any form of computer readable media forcommunicating information from one electronic device to another. Also,network 111 can include the Internet in addition to local area networks(LANs), wide area networks (WANs), direct connections, such as through auniversal serial bus (USB) port, other forms of computer-readable media,or any combination thereof. On an interconnected set of LANs, includingthose based on differing architectures and protocols, a router acts as alink between LANs, enabling messages to be sent from one to another. Inaddition, communication links within LANs typically include twisted wirepair or coaxial cable, while communication links between networks mayutilize analog telephone lines, full or fractional dedicated digitallines including T1, T2, T3, and T4, Integrated Services Digital Networks(ISDNs), Digital Subscriber Lines (DSLs), wireless links includingsatellite links, or other communications links known to those skilled inthe art. Furthermore, remote computers and other related electronicdevices could be remotely connected to either LANs or WANs via a modemand temporary telephone link. In essence, network 111 includes anycommunication method by which information may travel between computingdevices.

Additionally, communication media typically embodies computer-readableinstructions, data structures, program modules, or other transportmechanism and includes any information delivery media. By way ofexample, communication media includes wired media such as twisted pair,coaxial cable, fiber optics, wave guides, and other wired media andwireless media such as acoustic, RF, infrared, and other wireless media.

Server device 108 is a network device. Devices that may operate asserver 108 include various network devices, including, but not limitedto personal computers, desktop computers, multiprocessor systems,microprocessor-based or programmable consumer electronics, network PCs,server devices, network appliances, and the like. It should be notedthat while various devices are shown in a particular quantity, forexample, server 108 is shown as one device, in various embodiments theremay a different quantity of such devices, such two or more servers.There may even be two or more separate networks of servers. Thus, theinvention is not to be construed as being limited to a singleenvironment and other configurations, and architectures are alsoenvisaged.

Illustrative Client Device

FIG. 2 shows one embodiment of client device 200 that may be included ina system implementing the invention. Client device 200 may include manymore or less components than those shown in FIG. 2. However, thecomponents shown are sufficient to disclose an illustrative embodimentfor practicing the present invention. Client device 200 may represent,for example, one embodiment of at least one of client devices 101-104 ofFIG. 1 (and, accordingly, may include virtually any type of clientdevice).

As shown in the figure, client device 200 includes a processing unit(CPU) 222 in communication with a mass memory 230 via a bus 224. Clientdevice 200 also includes a power supply 226, one or more networkinterfaces 250, an audio interface 252, a display 254, a keypad 256, anilluminator 258, an input/output interface 260, a haptic interface 262,and an optional global positioning systems (GPS) receiver 264. Powersupply 226 provides power to client device 200. A rechargeable ornon-rechargeable battery may be used to provide power. The power mayalso be provided by an external power source, such as an AC adapter or apowered docking cradle that supplements and/or recharges a battery.

Client device 200 may optionally communicate with a base station (notshown), or directly with another computing device. Network interface 250includes circuitry for coupling client device 200 to one or morenetworks, and is constructed for use with one or more communicationprotocols and technologies including, but not limited to, global systemfor mobile communication (GSM), code division multiple access (CDMA),time division multiple access (TDMA), user datagram protocol (UDP),transmission control protocol/Internet protocol (TCP/IP), SMS, generalpacket radio service (GPRS), WAP, ultra wide band (UWB), IEEE 802.16Worldwide Interoperability for Microwave Access (WiMax), SIP/RTP, or anyof a variety of other wired or wireless communication protocols,including WiFi, Ethernet, and/or the like. Network interface 250 issometimes known as a transceiver, transceiving device, or networkinterface card (NIC).

Audio interface 252 is arranged to produce and receive audio signalssuch as the sound of a human voice. For example, audio interface 252 maybe coupled to a speaker and microphone (not shown) to enabletelecommunication with others and/or generate an audio acknowledgementfor some action. Display 254 may be a liquid crystal display (LCD), gasplasma, light emitting diode (LED), or any other type of display usedwith a computing device. Display 254 may also include a touch sensitivescreen arranged to receive input from an object such as a stylus or adigit from a human hand.

Keypad 256 may comprise any input device arranged to receive input froma user. For example, keypad 256 may include a push button numeric dial,or a keyboard. Keypad 256 may also include command buttons that areassociated with selecting and sending images. Illuminator 258 mayprovide a status indication and/or provide light. Illuminator 258 mayremain active for specific periods of time or in response to events. Forexample, when illuminator 258 is active, it may backlight the buttons onkeypad 256 and stay on while the client device is powered. Also,illuminator 258 may backlight these buttons in various patterns whenparticular actions are performed, such as dialing another client device.Illuminator 258 may also cause light sources positioned within atransparent or translucent case of the client device to illuminate inresponse to actions.

Client device 200 also comprises input/output interface 260 forcommunicating with external devices, such as a headset, or other inputor output devices not shown in FIG. 2. Input/output interface 260 canutilize one or more communication technologies, such as USB, infrared,Bluetooth™, or the like. Haptic interface 262 is arranged to providetactile feedback to a user of the client device. For example, the hapticinterface may be employed to vibrate client device 200 in a particularway when another user of a computing device is calling.

Mass memory 230 includes a RAM 232, a ROM 234, and other storage means.Mass memory 230 illustrates an example of computer readable storagemedia (devices) for storage of information such as computer readableinstructions, data structures, program modules or other data. Massmemory 230 stores a basic input/output system (“BIOS”) 240 forcontrolling low-level operation of client device 200. The mass memoryalso stores an operating system 241 for controlling the operation ofclient device 200. It will be appreciated that this component mayinclude a general-purpose operating system such as a version of UNIX, orINUX™, or a specialized client communication operating system such asWindows Mobile™, or the Symbian® operating system. The operating systemmay include, or interface with a Java virtual machine module thatenables control of hardware components and/or operating systemoperations via Java application programs.

Memory 230 further includes one or more data storage 248, which can beutilized by client device 200 to store, among other things, applications242 and/or other data. Applications 242 may include computer executableinstructions which, when executed by client device 200, perform actions.Other examples of application programs include calendars, searchprograms, email clients, IM applications, SMS applications, VOIPapplications, contact managers, task managers, transcoders, databaseprograms, word processing programs, security applications, spreadsheetprograms, games, search programs, and so forth. In some embodiments,applications 242 may include web browser 245, a media stack for the webbrowser, a content decryption module (CDM) for, inter alia, decryptingmedia content for the media stack, and an application running on browser245 such as a web application.

Various embodiments of client device 200 may include applications 242.These stored applications are processor-executable code encoded on aprocessor-readable medium, which, when executed by CPU 222, enableactions to performed in accordance with the processor-executable code.In some embodiments, web browser 245 (and/or other applications 242) mayperform steps such as those illustrated in the flowcharts below.

Although the discussion of various embodiments above has described theperformance of actions implemented in software, for example by means ofprocessor-executable code encoded on a processor-readable medium, which,when executed by CPU 222, enable actions to performed in accordance withthe processor-executable code, in various embodiments, actions, may insome embodiments, rather than being performed only by executed software,may instead be performed based on hardware only, or by a combination ofhardware and software.

Illustrative Network Device

FIG. 3 shows one embodiment of a network device 300, according to oneembodiment of the invention. Network device 300 may include many more orless components than those shown. The components shown, however, aresufficient to disclose an illustrative embodiment for practicing theinvention. Network device 300 may represent, for example, server 108 ofFIG. 1.

Network device 300 may include processing unit 312, video displayadapter 314, and a mass memory, all in communication with each other viabus 322. The mass memory generally includes RAM 316, ROM 332, and one ormore permanent mass storage devices, such as hard disk drive 328, tapedrive, optical drive, and/or floppy disk drive. The mass memory maystore operating system 320 for controlling the operation of networkdevice 300. Any general-purpose operating system may be employed. Basicinput/output system (“BIOS”) 318 may also be provided for controllingthe low-level operation of network device 300. As illustrated in FIG. 3,network device 300 also can communicate with the Internet, or some othercommunications network, via network interface unit 310, which may beconstructed for use with various communication protocols including theTCP/IP protocol. Network interface unit 310 is sometimes known as atransceiver, transceiving device, or network interface card (NIC).

The mass memory as described above illustrates another type ofcomputer-readable/processor-readable media, namely computer-readablestorage media. Computer-readable storage media (devices) may includevolatile, nonvolatile, removable, and non-removable media implemented inany method or technology for storage of information, such as computerreadable instructions, data structures, program modules, or other data.Examples of computer-readable storage media include RAM, ROM, EEPROM,flash memory or other memory technology, CD-ROM, digital versatile disks(DVD) or other optical storage, magnetic cassettes, magnetic tape,magnetic disk storage or other magnetic storage devices, or any otherphysical medium which can be used to store the desired information andwhich can be accessed by a computing device.

Data stores 354 may include a database, text, spreadsheet, folder, file,or the like. Data stores 354 may further include program code, data,algorithms, and the like, for use by a processor, such as centralprocessing unit (CPU) 312 to execute and perform actions. In oneembodiment, at least some of data and/or instructions stored in datastores 354 might also be stored on another device of network device 300,including, but not limited to cd-rom/dvd-rom 326, hard disk drive 328,or other computer-readable storage device resident on network device 300or accessible by network device 300 over, for example, network interfaceunit 310.

The mass memory also stores program code and data. One or moreapplications 350 may be loaded into mass memory and run on operatingsystem 320. Examples of application programs may include transcoders,schedulers, calendars, database programs, word processing programs,Hypertext Transfer Protocol (HTTP) programs, customizable user interfaceprograms, IPSec applications, encryption programs, authenticationprograms, security programs, SMS message servers, IM message servers,email servers, account managers, and so forth. In some embodiments, asdiscussed in greater detail below, application 350 may includeapplications for providing a content authorization service, and mayprovide a license to an authorized requesting client application.

Generalized Operation

The operation of certain aspects of the invention will now be describedwith respect to FIG. 4.

FIG. 4 illustrates a flowchart of an embodiment of process 470. After astart block, the process proceeds to block 484, where a client webbrowser of a client is employed to instantiate a browser plugin for theclient web browser. The process then moves to block 486, where theclient web browser is employed to obtain a reference to the browserplugin. (In some embodiments, the act at block 486 happens inherently asa part of the act of block 484. In other embodiments, the acts at block484 and block 486 are separate acts from each other.) The process thenproceeds to block 487, where a command is given to the browser pluginvia the reference to the browser plugin. In some embodiments, more thanone such command may be given. The process then proceeds to a returnblock, where other processing is resumed.

In various embodiments, the browser plugin may be a browser plugin forperforming virtually any web feature or browser feature. The browserplugin is instantiated by the web browser, not the web page. The browserplugin is a plugin for the browser, not a media engine plugin. Thebrowser plugin is providing functionality for the browser rather thanproviding part of the page content. The browser plugin is an in-pageplugin that is invoked by HTML. In some embodiments, the browser mayinstantiate the plugin by injecting code into the web page, but this isstill the browser instantiating the browser plugin. By having thebrowser, rather than the web page, instantiate the browser plugin, thereis no need for the web pages to include such elements or scripts withinthem (in some embodiments, the browser injects such elements or scriptsinto the web page, but in this case, the web page did not need toinclude such elements before the browser injects them into the webpage). Because the browser, rather than the web page, instantiates thebrowser plugin, the pluggable functionality can be used on any web pageswithout modifications to the web pages.

In other various embodiments, rather than injecting the appropriate codeinto the page, the appropriate elements may instead instantiate a plugindirectly by instantiating the native browser code that represents andmanages the plugin, may inject the elements into the shadow DOM, and/ormay include elements in a separate, hidden web page or frame.

In some embodiments, the browser plugin is not accessible by the webpage. In some embodiments, the web page is not able to detect thepresence of the browser plugin.

As discussed above, in some embodiments, the browser may inject theappropriate HTML, JavaScript, JavaScript variables and/or objects, etc.into the web page, appropriate elements into the DOM (pagerepresentation), or representations of the appropriate elements into thebrowser's internal representation of the page.

In some embodiments, the element it may be injected in a more “global”location, such as a <body> or <head> tag. In some embodiments, thebrowser may inject and/or run script that instantiates the browserplugin.

As discussed above, at block 486, the client web browser obtains areference to the browser plugin. In some embodiments, the reference is apointer to the browser plugin, such as a C++ pointer. In otherembodiments, the reference to the plugin may be a name, type, or otheridentification to find and access the browser plugin at a subsequenttime.

At block 487, the browser gives one or more commands to the browserplugin using the reference obtained at block 486. The nature of thecommand(s) varies in different embodiments depending on the nature ofthe browser plugin and the functions performed by the browser plugin,which may vary considerably in different embodiments.

The pluggable functionality of the browser plugin may extendcapabilities for or related to one or more elements or even non-elementcapabilities in the web browser.

As discussed above, in some embodiments, the browser instantiates thebrowser plugin directly by instantiating the native browser code (e.g.,C++ or other suitable native browser code) that represents and managesthe browser plugins. This would also load the plugin code (e.g.,DLL/SO).

In some embodiments, the appropriate item may be injected within theelement for which the plugin functionality is used. As discussed above,in some embodiments, this may be done by injecting the item into theshadow DOM of an element. By injecting the item into the shadow DOM ofan element, the item is not accessible by other elements and script inthe page, and they may not even be able to detect its presence.

In these embodiments, if an element has a shadow DOM by default (e.g.,<video> elements in the layout/rendering engine software, e.g., WebKit),it may be injected into the existing shadow DOM.

In some embodiments, the browser may use mechanisms to hide the elementor script from the web page's/application's elements and/or scripts. Insome embodiments, this might include supporting a non-standard elementor naming scheme that the browser uses to indicate that the element orscript should not be accessible to elements and/or scripts in thepage/application. For example, in some embodiments, elements may benamed in a certain manner to indicate that elements named in that mannerare not accessible to elements and/or scripts in the page/application.

In some embodiments, the browser may block every call that might accessthe hidden element, and for any call that would otherwise access theelement, the access may be blocked, an exception may be thrown, or anindication that the element cannot be found may be provided in responseto the call.

Even in embodiments in which elements are injected into the DOM toinstantiate the plugin, the process is still such that it is entirelytransparent to the web page that a plugin is being used in thebackground, and all of the normal functionality of the web page stillworks as normal.

In some embodiments, the browser plugin may be implemented using aplugin architecture such as Active X, Netscape Plugin ApplicationProgramming Interface (NPAPI), Pepper Plugin API (PPAPI), or the like.

FIG. 5A illustrates a flowchart of an embodiment of process 570, whichmay be employed as an embodiment of process 470 of FIG. 4. After a startblock, the process proceeds to block 561, where a browser plugin isregistered with a client web browser. The process then proceeds todecision block 563, where a determination is made as to whether there isa need for the browser plugin. If not, the process remains at decisionblock 563, where the need for the browser plugin is monitored. If,however, the determination at decision block 563 is positive, theprocess moves to block 580, where the browser plugin is instantiated anda reference to the browser plugin is obtained.

The process then advances to block 587, where a command is given to thebrowser plugin via the reference to the browser plugin. In someembodiments, there is a set of APIs employed in the plugin framework forwhich to give commands to the browser plugin via the reference. Theprocess then moves to decision block 598, where a determination is madeas to whether the browser plugin is still needed. If so, the processreturns to block 587, where another command is given to block 587, andthe process then advances to decision block 598 again.

At decision block 598, if it is determined that the browser plugin is nolonger needed, the process proceeds to block 599, where the sub-tree ofthe DOM is destroyed. Destroying the sub-tree causes the sub-tree to beunrendered, so that the browser plugin instance is destroyed. Theprocess then proceeds to a return block, where other processing isresumed.

In some embodiments, there is no step of destroying the sub-tree. Forexample, in some embodiments, an internal representation of the browserplugin is used.

FIG. 5B illustrates a flowchart of an embodiment of process 580B, whichmay be employed as an embodiment of the process at block 580 of FIG. 5A.After a start block, the process proceeds to block 584, where a sub-treeof the DOM is created. The sub-tree is included in the rendering of thedocument, and is therefore part of the rendering tree, but the sub-treeis inaccessible from the DOM. Also, the sub-tree includes one or more<object> or <embed> tags such that the tags, when rendered, willinstantiate the browser plugin.

The process then moves to block 585, where the sub-tree is rendered,which causes the browser plugin to be rendered. The process thenadvances to block 586, where the browser gets a reference to the browserplugin. In some embodiments, the reference is provided in a callback asthe browser plugin is being rendered. The process then proceeds to areturn block, where other processing is resumed.

In some embodiments, the sub-tree in the DOM created at block 584 is inthe shadow DOM. The code for rendering the shadow DOM is implementedinside the browser. In other embodiments, the sub-tree is created in theDOM of a separate, hidden, secret document (e.g., web page or frame)that is hidden and inaccessible from the primary web page/webapplication and that is not visible to the user. In some embodiments,the separate, hidden web page may be as simple as just, for example,nothing more than: <!DIOCTYPE html><head><metacharset=‘UTF-8’></head><body><objecttype=“+pluginType+”></object></body>.

In some embodiments, there is nothing regarding the browser plugin inthe main page of the DOM, so that the only references to the browserplugin are in some portion of the browser.

At decision block 563, the need for a browser plugin is different invarious embodiments. In some embodiments, the browser plugin could berequired for any web page. In some embodiments, the need for the browserplugin could be triggered by the mark-up on the web page or because ofsome action the script took on the web page. The need may be triggeredbased on one or more specific actions happening or not happening invarious embodiments.

In some embodiments, the browser plugin is a content decryption module(CDM), and at decision block 563, the determination is positive when anaddKey function is called in a script of the web page, indicating thatdecryption/content protection is needed. In other embodiments, thedetermination may be based on some other step. For example, thedetermination may be a determination of whether the first step in thelicense request has occurred, where this first step is different indifferent embodiments. For example, in some embodiments, the process maybe started by generateKeyRequest, or the creation of a MediaKeys objectmay begin the process.

Further, the invention is not limited to a determination related to thelicense request process, because this is just one specific embodiment ofa browser plugin, and the browser plugin may be used for virtually anyweb function or browser function in various embodiments. For example, insome embodiments, the browser plugin provides the browser function ofweb syncing that syncs a user's bookmarks and/or tabs between computers.In other embodiments, the browser plugin may provide functionality forvarious web functions, such for the image tag in some embodiments.Further, even in the example of an embodiment in which the browserplugin is a CDM, in some embodiments, the addKey function is notnecessarily required for indicating the need for the browser plugin—forexample, it could be any cryptography tag that indicates the need forthe CDM browser plugin.

In some embodiments, the browser plugin may only use or be allowed touse by design and/or policy a subset of the plugin infrastructure. Forexample, in some embodiments, certain browser plugin(s) may be deniednetwork access. In some embodiments, some browser plugin(s) may beallowed to be run only by particular restricted APIs within the browser.A browser plugin is still a browser plugin even if functionality isrestricted and/or the set of supported APIs is changed in some way.

As discussed above, at block 561, the browser plugin is registered withthe client web browser. The browser plugin is registered with the clientweb browser in such a way that the browser can load the browser plugingiven a type string. In some embodiments, the browser maintains orpopulates a table of key system names (which may be strings in someembodiments) to plugin types (which may be strings in some embodiments).

In various embodiments, “key system names” could be something elseentirely. For example, instead of a key system name, it someembodiments, the table may store a list of codes for the image tags. Insome embodiments, a table is not needed.

FIG. 6 shows system 600, which may be employed as an embodiment ofsystem 100 of FIG. 1. System 600 includes license server 608, web server609, content delivery network (CDN) 607, and client device 601. Licenseserver 608, web server 609, and CDN 607 may each, for example, be one ormore server devices such as server device 108 of FIG. 1 and/or networkdevice 300 of FIG. 3. Client device 601 may be, for example, anembodiment of client device 101-104 of FIG. 1 and/or client device 200of FIG. 2.

Client device 601 includes application 644, content decryption module(CDM) 649, platform 643, and browser 645. Browser 645 includes mediastack 646 and network stack (Net) 657.

CDM 649 may be employed as an embodiment of a browser plugin that isinstantiated by a process such as one of the processes discussed abovewith regard to FIG. 4 and/or FIGS. 5A-B. In some embodiments, CDM 649may be instantiated after a cryptographic function such as addKey, orthe like, is called.

CDM 649 performs decryption of media content in communication with mediastack 646. Application 644 is a media playback control application.

Media stack 646 performs and/or controls decoding of media content (inconjunction with CDM 649, which performs the actual decoding in someembodiments). In some embodiments, media stack 646 is a set of connectedmedia processing and rendering modules used for converting digital mediadata into human-perceptible representations (e.g., moving picturesand/or sound). Media stack 646 performs and/or controls functions suchas de-multiplexing, decryption, and rendering in some embodiments (inconjunction with CDM 649 in some embodiments). In some embodiments,media stack 646 has substantially no other logic, but just renders whatit is fed, and can therefore be used for all types of media playbackapplications in an interchangeable fashion. In some embodiments, certainfunctions such as decryption are not performed directly by media stack646 itself, but by CDM 649, which is a separate module that performscertain functions, such as decryption, under the control of media stack646.

Application 644 instructs media stack 646 to playback media content. Insome embodiments, application 644 includes computer-executable code thatimplements substantially all of the logic required to play back media ina particular context, including user interface logic, subtitle controlinformation, control of the acquisition of keys, and/or the like, butnot processing and rendering. The processing and rendering is insteadperformed by media stack 646 and/or by separate modules under thecontrol of media stack 646, including CDM 649. In some embodiments, therendering is performed by a part of browser 645 other than media stack646. In other embodiments, the rendering is performed by another part(hardware or software) of the client. Together, media stack 646 andapplication 644 both reside in client device 601 and operate as a clientmedia player. Media stack 646 and application 644 are distinct programsor binaries or libraries or scripts, etc., where media stack 646 can bere-used. Media stack 646 stack is part of an application framework,together with other modules that implement user input, graphics output,network 1/O etc. The application framework exposes standard abstractinterfaces for these functions to application 644. Application 644 maybe a web application for playback of media using the HTML media elementsidentified in HTML5 (and/or future versions of HTML) by HTML media tagssuch as <media>, <video>, and <audio> (and/or future HTML mediaelements), where the web application includes a scripting language(e.g., JavaScript) and HTML or a mark-up language derived from HTML(e.g., mark-up languages based on supersets/subsets/slices/extensions ofHTML).

This particular separation between media stack 646 (as part of theapplication framework) and application 644 is useful because the mediastack implementation is typically specific to the type of computerhardware platform it executes on, and therefore is implemented in a waythat is strongly connected to the operating system. The same holds foruser input, graphics output, network I/O, etc. In some embodiments,media stack 646 is specific to a particular type of content protection.Application 644, however, can be the same across many different computerplatforms when the underlying application framework abstracts access touser input, network, graphics, media stack, etc.

In some embodiments, when application 644 acquires a license, it does soin communication with one or more servers. In some embodiments, webserver 608 may handle requests or send directly to license server 609.In some embodiments, application 644 may communicate directly withlicense server 609.

In some embodiments, media stack 646 may acquire media content specifiedby application 644 via network stack 647, where network stack 647acquires the media content from CDN 607.

A content encryption key may be generated employing any of a number ofencryption/decryption symmetric mechanisms, including, but not limitedto Advanced Encryption Standard (AES), RSA, RC6, IDEA, DES, RC2, RC5,Skipjack, and any other symmetric encryption algorithm. Moreover, suchencryption algorithms may use, where appropriate, cipher block chainingmode, cipher feedback mode, CBC cipher text stealing (CTS), CFB, OFB,counter mode, and/or any other block mode. In some embodiments, contentencryption keys are generated employing an at least 128-bit AESencryption/decryption algorithm. However, content encryption keygeneration is not limited to symmetric key mechanisms, and asymmetrickey mechanisms may also be employed without departing from the scope ofthe present invention. Typically, where the content encryption key is asymmetric encryption key, such content encryption keys are also referredto as decryption keys, as the same key may be used to both encrypt andto decrypt the content.

In additional to decryption, in various embodiments, CDM 649 may alsoperform such functions as DRM, content protection, license exchange orprocessing (including e.g., license request generation), decoding,de-multiplexing, and/or the like. In some embodiments, CDM 649 performsdecoding for codecs not supported by browser 645. While media stack 646generally performs rendering in many embodiments, in some embodiments,CDM 649 is employed to perform secure rendering.

In terms of DRM and/or content protection, in some embodiments, CDM 649may protect the buffers and protect the decryption key through softwaremethods. In some embodiments, CDM 649 has a secret key that CDM 649 usesto decrypt the license and obtain the content key, and CDM 649 protectsCDM 649's secret key. In some embodiments, CDM 649 employs the contentkey to decrypt the corresponding media. In some embodiments, CDM 649must also protect the content key once CDM 649 has decrypted the contentkey from the license. In some embodiments, CDM 649 also protects thecompressed, decrypted frames. In some embodiments, the memory isscrambled such that the decrypted but compressed frames are notavailable in memory at any time. In some embodiments, the decompressedframes may also be protected. In some embodiments, CDM 649 may alsoprotect and/or enforce other license provisions, such as the length oftime the license allows particular video content to be viewed. In someembodiments. CDM 649 determines when the license has expired, and that anew license is needed when the license has expired.

Media stack 646 controls various functions of CDM 649, such as when todecrypt and decode, when to render if CDM 649 performs rendering, whento generate a license request, and the like. However, in someembodiments, CDM 649 may also perform DRM and/or content protectionfunctions that are not necessarily directly controlled or initiated bymedia stack 646, such as those DRM and/or content protection functionsdiscussed in the previous paragraph.

In some embodiments, CDM 649 performs decryption but not decoding. Insome of these embodiments, media stack 646 may provide encrypted data toCDM 649, CDM 649 decrypts the media and provides the decrypted media tomedia stack 646, and media stack 646 then performs decoding on thedecrypted media. In other embodiments, as previously discussed, CDM 649performs both decryption and decoding. In some embodiments, after mediastack 646 sends CDM 649 encrypted media, CDM 649 decrypts and decodesthe encrypted media, and then sends the decrypted media to securehardware (e.g., a secure surface) rather than returning the decryptedmedia to media stack 646. In some embodiments, CDM 649 uses a securepipeline for decryption, decoding, and/or rendering.

In some embodiments, CDM 649 is sandboxed. In some embodiments, CDM 649is sandboxed, but can perform particular unsandboxed operations via aspecial channel. In some embodiments, CDM 649 is sandboxed but canperform particular unsandboxed operations via a broker.

Content protection can involve accessing the system in ways web contentusually should not need, which could lead to system vulnerabilities. IfCDM 649 is sandboxed, these system vulnerabilities can be prevented.Also, sandboxing can provide privacy protection, so that CDM 649 cannotgrab personal identifiable information or the like. By employing asandboxed CDM that is a separate binary from browser 645, securedecryption and/or DRM may be performed without polluting browser 645 orusing platform capabilities; platform independent decryption/DRM may beperformed both in the logical (OS-independent) and architecture/binarysense; and content protection, decryption, and/or the like can beseparate from browser 645 and the application 644, all while browser 645handles playback.

Sandboxing only allows code execution that cannot make persistentchanges to the computer, and sandboxed code execution cannot accessinformation that is confidential. With sandboxing, code that is runningcannot make changes to the system, and no matter what it does, does nothave access to change the system. A sandboxed program typically cannotrun commands that are not authorized, and might also be able to changethe system, but only via strict APIs—the sandboxed code is unablecreate, modify, or delete a file using normal system calls. Thesandboxed code can only change the system through an API, and thesandboxing entity can decide which kinds of accesses to allow.

In some embodiments, CDM 649 may be a sandboxed browser plug-in, andimplemented as a Pepper/PPAPI plug-in. Traditionally, plug-ins,including Pepper, are used to display content on the page. However, insome embodiments, Pepper is just used as a framework to execute codeseparate from the web browser within a sandbox.

Use of PPAPI provides an architecture that enables runningout-of-process, sandboxing, run-time loading, DLL/shared object loading,browser-provided functionality, sandbox escape functionality, and othercapabilities for the browser plugin.

In some embodiments, CDM 649 is not sandboxed, and CDM 649 can write outto a secure pipeline. In some embodiments, CDM 649 is not sandboxed, andit does decryption and decoding in a secure pipeline. (Secure pipelinesmay also be used when the CDM is sandboxed).

In other embodiments, CDM 649 may be a browser plug-in implemented, forexample, in Netscape Plugin API (NPAPI) or ActiveX.

FIG. 7 illustrates a flowchart of an embodiment of process 770, whichmay be employed as an embodiment of process 570 of FIG. 5A. After astart block, the process proceeds to block 761, where a CDM browserplugin is registered with a client web browser. The process thenadvances to block 772, where the client browser loads the webapplication. The web application may include a scripting language (e.g.,JavaScript) and HTML. The process then moves to block 773, where theclient browser discovers an HTML media tag (e.g., <video> or <audio>)pointing to media content.

The process then advances to block 774, where the web applicationinstructs the media stack of the client browser to initiate playback ofthe media content. In some embodiments, the web application may containan autoplay attribute, in which case the browser parses the webapplication, discovers the autoplay attribute, and causes the mediastack to autoplay the media content. In other embodiments, there is noautoplay attribute for the media content, and the web applicationinstructs the media stack when to play media content. The media stack isinstructed to play the media content in a time and manner that is inaccordance with the web application. For example, in some embodiments,the web application instructs the media stack to play the media contentwhen a “play” button is pressed by the user.

The process then proceeds to block 775, where the media stack starts toprocure the media content that the media stack was instructed to playback (e.g., through file reading, or progressive or adaptive streaming).

The process then advances to block 776, where the media stack fires anevent to the web application, where the event indicates that a licenseis needed to begin or continue playback of the media content. Theprocess then proceeds to block 780, where the CDM browser plugin isinstantiated, and a reference to the CDM browser plugin is obtained. Inone embodiment, the process at block 780 occurs substantially as process580 of FIG. 5B.

The process then advances to block 787, where the license requestprocess occurs. In some embodiments, the web application sends a requestfor a license request to the media stack, and then the media stack sendsthe request for a license request to the CDM. In some embodiments, theCDM sends a license request to the media stack in response to receivingthe license request from the media stack. In some embodiments, thelicense request must come from the CDM, because, in these embodiments,for security purposes, the license server requires a signature that onlythe CDM can provide in order to provide the license. Then the mediastack sends the license request to the web application.

In some embodiments, the step of block 780 may occur after or during thestep of block 787. For example, in some embodiments, the step at block780 may be caused in response to a request to generate a license requestor addKey within the step at block 787 that causes the step at block 780to occur.

The process then moves to block 791, where the web application gets thelicense. As discussed in greater detail below, the web application mayget the license in a variety of different ways in different embodiments.For example, in some embodiments, the application acquires the licensevia communication with one or more servers. In some embodiments, thelicense may be found locally or on a local network. In some embodiments,the license is acquired in accordance with a digital right management(DRM) scheme, or other content protection system. In other embodiments,the license could be stored in the web application. In some embodiments,a license is used to establish the content key in the media stack incontent protection mechanisms where the key is not transmitted in theclear, and the key is extracted from or derived from the license data.

The web application is configurable to different types of contentprotection through the same framework. The web application defines aprotocol or process and standardizes the interfaces so that the processcould be configured to work with any of a variety of like underlyingsort of technologies, but the interface is the same regardless of thecontent protection system used.

Since the license acquisition occurs not in the media stack but in theweb application, the web application has control over the error handlingfor the license acquisition, and the web application can handle errorconditions and the like.

The process then advances to block 792, where the web application sendsthe license to the media stack. The process then proceeds to block 793,where the media stack receives the license. The process then advances toblock 794, where the media stack sends the license to the CDM. In someembodiments, the step at block 794 may be accomplished by commands givento the CDM via the reference. The media stack and the CDM are distinctbinaries from each other. The process then moves to block 795, where themedia stack sends encrypted data to the CDM. The encrypted data may beaccompanied by parameters, including which license the encrypted data isassociated with.

The process then proceeds to block 796, where the encrypted data isdecrypted and decoded by the CDM. This may be accomplished by commandsgiven to the CDM browser plugin via the reference. In some embodiments,the media content is first decrypted and then decoded, and in otherembodiments, the media content is first decoded then decrypted. In someembodiments, the encrypted media content it sent from the media stack tothe CDM one frame at a time, and the CDM decrypts and decodes the mediacontent one frame at a time. In some embodiments, the CDM performs thedecryption but not the decoding, and the decoding is instead performedby the media stack after the decrypted media is sent back to the mediastack. What happens to the decrypted data varies in various embodiments.In some embodiments, the decrypted data is provided to the media stackfor rendering. In some embodiments, the decrypted data is provided to asecure pipeline.

The process then advances to block 799, where the sub-tree of the DOM isdestroyed. As previously discussed, in some embodiments, this step doesnot occur. The processing then proceeds to a return block, where otherprocessing is resumed.

Many variations to the exact process flow illustrated in FIG. 7 arewithin the scope and spirit of the invention. For example, in someembodiments, the web application may determine that the media isencrypted. Accordingly, rather than the web application instructing themedia stack to initiate playback right away, in this case the webapplication can instead get the license, and after the web applicationgets the license, the web application can instruct the media stack toinitiate playback along with sending the media stack the data thatincludes the license. In some embodiments, the media tags may specifythat the media is encrypted. As previously discussed, the steps mayhappen in a different order than shown in FIG. 7, for example, the stepof block 774 may occur earlier or later than shown, as previouslydiscussed. Further, in some embodiments, the application may determinewithout notification that a license is needed, rather than having toencounter something in the file before determining that a license isneeded.

In some embodiments, such as a key rotation scheme, the media stack canfire an event each time a new key is needed, and the application canprovide the new key to the media stack.

Process 770 may be applied to local content, to content that isdownloaded and then played, and/or to streaming content. Process 770 isnot specific to any particular form of content protection, but may beapplied to various forms of DRM and other forms of content protection indifferent embodiments. Process 770 can support a wide range of controlsystem types, including traditional DRM systems, conditional accesssystems, simple key establishment without the need for DRM servers, andkey distribution systems based on DRM systems.

In some embodiments, process 770 may be used for viewing commercialcontent, including commercial content protected by a content protectionmechanism such as DRM, where the commercial content may include moviesor the like. In some embodiments, the media may be accessed via awebpage employing HTML5, or a future version of HTML that also supportsmedia tags, where the media content is accessed in an HTML media tagsuch as <video> or <audio>. The media content, which is protected bysome sort of content protection, such as encryption, DRM, and/or thelike, can be accessed in a browser with an HTML media tag, with themedia accessible, controllable, and configurable by the web application,where the media content can be streamed to the browser, downloaded,provided by the application, or local. In some embodiments, the webapplication provides application level flexibility to implement theauthorization exchange, and all of the HTML5 security mechanisms may beused for network transactions.

In some embodiments, one attribute (authorizationData) and one event(authorizationNeeded) is added to the HTML5 media elements, as follows.In some of these embodiments, the design adds one new attribute to mediaelements named authorizationData. In some embodiments, the purpose ofthis attribute is to provide the CDM with the necessary information toinitialize itself and enable playback of the requested content (e.g., adecryption key). In some embodiments, authorizationData may be a methodthat provides the data to the media element. The attributeauthorizationData and the event authorizationNeeded may have differentnames in different embodiments. For example, in FIG. 6, they arereferred to as addKey( ) [as a called function rather than an attribute]and needkey, respectively.

The authorizationNeeded event fires when the media stack underneath themedia element discovers the need for fresh authorization data to startor continue playback. This event is accompanied by one or more blobs ofdata generated by the media stack that is potentially opaque to theapplication. The format of the data may be dependent on the contentcontrol mechanism(s) in the CDM and/or content format.

The authorizationNeeded event is an embodiment of the event fired atblock 776 of process 770. In some embodiments, the authorizationNeededevent also contains supplemental data that is specific to the contentcontrol mechanism and/or content. The supplemental data can be opaque tothe application—it only needs to be understood by the entity thatcreates the license data, which could be a network service in someembodiments.

The web application uses the information mentioned above to procure therequired content control data (either through an application-specificmechanism or through a content-control-specific mechanism). This couldhappen through in-client processing, querying (e.g. a password),retrieval from storage, or a network request to a service. TheauthorizationNeeded event can fire multiple times during a singleplayback session, e.g., for key rotation.

The acquired content control data is provided to the media element viathe authorizationData attribute. Once the data is present and correctlyverified by the media stack, playout starts. In order to avoid playoutdelays due to latencies incurred when acquiring content control data,existing preload mechanisms can be used.

In some embodiments, the authorizationNeeded event contains an array ofthe following tuple: type and data, where type is an identifier ofcontent control mechanism, and data is a byte array containing contentsdependent on content control mechanism to enable application to acquireauthorization data. In some embodiments, the authorizationData attributeincludes a byte array in which the contents are dependent on contentcontrol mechanism, which enables the media stack to play content, and/orcontent data format.

In one possible embodiment of an application of the authorization dataacquisition mechanism, content is encrypted using a content key, and asecure key distribution system stores the key. In some embodiments, themedia stack contains client code of this secure key distribution system(though a pluggable mechanism or platform capabilities in someembodiments), and the content provider runs a key distribution serviceas a counterpart.

In some of these embodiments, the content control system uses: a“challenge” data structure generated on the client and a “license” datastructure generated on the server using the content key and the clientpublic key. The “challenge” data structure typically containsinformation about the content to be played for retrieval of the correctkey, and information about the client CDM (client ID, client type,public key for encryption of the content key for transport).

In these embodiments, the media stack detects that the content isencrypted, and can be decrypted using the secure key distributionsystem's client CDM. The content key is acquired through a networktransaction. Since the application has not yet set the authorizationDataattribute of the media element to a valid “license” data structure, themedia stack generates a “challenge” data structure and serializes itinto a byte stream.

In these embodiments, the authorizationNeeded event gets the followingtwo attributes: (1) type=(<string or numeric identifier for the securekey distribution system>); and (2) data=<challenge bytestream>, andfires.

In these embodiments, the application catches the event using a handlerfor this event. In the handler, the web application generates a requestto the streaming service's license server, using an existingauthentication mechanism (e.g., domain cookie) to authorize the requeston the server, and the opaque data generated by the CDM. In someembodiments, the content control mechanism may choose to invalidate theauthorization data after a certain number of uses, therefore disallowingreplay of previously issued authorization data, and in consequenceenforcing a requirement of fresh authorization for each playback.

In these embodiments, authorization depends on the streaming service'sbusiness rules. At the minimum, licenses could be handed out toeveryone. In a service like this, the content still cannot be copied,and giving out rights to play back can be stopped at any time (e.g. whenthe service's distribution rights for this content end). Other servicesmay require customer authentication, and even others may imposerestrictions on number of devices and concurrent usage.

In these embodiments, if authorization is successful, the license servermay use the content identification data in the “challenge” datastructure to retrieve the content key for the content to be played fromits database, and use the client key to generate a “license” datastructure, which is handed back to the application in the response. Theapplication installs the opaque license data into the authorizationDataattribute of the media element, and playout starts after successfulverification of the license data and extraction or derivation of thecontent key from the license data by the media stack. In someembodiments, the CDM is responsible for: the security of the decryptedcontent, the security of the content key, the security of the client CDMkeys that can be used to decrypt license data, and secure disposal ofthe content key after playback has ended. In some embodiments, theopaque license data contains all of the necessary information to playall streams of the content in question that are authorized to therequesting user on the target device. For example, if different streamsof some particular content are encrypted with different keys, thelicense contains all of the keys and the necessary information toassociate it with the correct streams.

In some of these embodiments, the system can be extended to allowoffline playback without changing the media stack implementation of thecontent control system, e.g. by retrieving the license from storage.

In these embodiments, a simple offline playback system allows the userto “pin” content to the client device while the device is connected. Thecontent data (one embodiment thereof, e.g., at appropriate bitrate andquality for the target device) is downloaded from the server in itsentirety and stored in local storage. The application uses a mediaelement to initiate preload of playback for the content data in localstorage, which triggers the authorization data retrieval mechanism. Theauthorization data is retrieved by the application as in the streaminguse case, but not installed in the authorizationData attribute yet. Itis cached in local storage until offline playback is initiated.

In these embodiments, if required for management of the storedauthorization data, the content protection system can support thetransmission of additional information on top of the opaqueauthorization data blob to the web application, e.g. content ID,expiration date etc., e.g. through the network protocol that also servesto transmit the authorizationData blob. This mechanism can beproprietary to the content protection system in some embodiments.

In these embodiments, when playback is initiated, the applicationretrieves the authorization data from its internal storage and installsit in the media element, allowing playout to proceed.

Returning to FIG. 6, as discussed above, the event authorizationNeededand the attribute authorizationData are instead replaced by the eventneedkey and the function addKey( ), respectively. Application 644 mayuse Get Key to acquire a key from a server, which may in turn respondwith an encrypted key via Key from the server to application 644. Thekey may be provided from application 644 to media stack 646 via addKey(), and from media stack 646 to CDM 649 via SetKey.

In some embodiments, canPlayType( ) is extended to provide basicinformation about content control systems supported by the browser.

Media stack 646 may provide an encrypted frame for CDM 649 to decryptvia Decrypt Frame. CDM 649 then decrypts the encrypted frame, andprovides the decrypted frame back to media stack 646 via Frame.

In some embodiments, a generateKeyRequest( ) function may be employedfrom Application 644 to media stack 646. A Key Request may be sent frommedia stack 646 to application 644 in response to thegenerateKeyRequest( ) function.

FIG. 8 shows an embodiment of web page 843 and a browser implementation844 of the web page. FIG. 8 shows a particular embodiment in which theshadow DOM is employed. Browser implementation 844 resides in the webbrowser, and includes page implementation 846 and <video> implementation847. Web page/DOM 843 includes script 849 and <video> tag 869. Web page843 is loaded by the web browser.

When <video> tag 869 of DOM 843 is rendered, the rendered <video>element has controls that are not accessible via DOM 843, although theuser can see the controls. The elements that render these controls,which are inaccessible to DOM 843, are provided during rendering by<video> implementation 847, which inserts the controls in the shadowDOM.

When AddKey is called by page/DOM 843, <video> implementation 847intercepts the AddKey call. The <video> implementation 847 then insertsa tag (e.g., an object tag) for the plugin in the shadow DOM containingthe controls, which causes instantiation of the browser plugin. The<video> implementation 847 then provides the browser plugin with thekey.

In this way, in some embodiments, the tag for instantiating the browserplugin may be placed in existing shadow DOM that is already implementedfor media control, and the tag (e.g., <object> tag) for instantiatingthe browser plugin reference can exist in the shadow DOM like a normalobject tag but that is inaccessible by the DOM or the web application orthe script.

The above specification, examples, and data provide a description of themanufacture and use of the composition of the invention. Since manyembodiments of the invention can be made without departing from thespirit and scope of the invention, the invention also resides in theclaims hereinafter appended.

What is claimed is:
 1. A method, comprising: employing a client webbrowser of a client to instantiate, responsive to an action initiated bya web page received by the web browser, a browser plugin for the clientweb browser, the browser plugin being instantiated by the client webbrowser based on one or more elements in a local resource other thanfrom within the web page; employing the client web browser to obtain areference to the browser plugin the reference to the browser pluginbeing inaccessible from the web page; and providing a command to thebrowser plugin via the reference to the browser plugin.
 2. The method ofclaim 1, wherein the reference to the browser plugin includes at leastone of a pointer to the browser plugin, a name of the browser plugin, oran identification to find access the browser plugin.
 3. The method ofclaim 1, wherein the command to the browser plugin is a commandassociated with obtaining a key for decrypting encrypted media content.4. The method of claim 1, further comprising: registering the browserplugin with the client web browser.
 5. The method of claim 1, whereinthe browser plugin is sandboxed.
 6. The method of claim 1, wherein thebrowser plugin is an in-page plugin that is invoked by Hypertext MarkupLanguage Protocol.
 7. The method of claim 1, further comprising: givinganother command to the browser plugin via the reference to the browserplugin.
 8. The method of claim 1, wherein instantiating the browserplugin is accomplished by injecting, based on the action initiated fromwithin the web page, the one or more elements into a shadow documentobject model.
 9. The method of claim 1, wherein instantiating thebrowser plugin is accomplished by injecting elements into the web page.10. The method of claim 1, wherein instantiating the browser plugin isaccomplished by injecting, based on the action initiated from within theweb page, the one or more elements into a hidden web page that isseparate from the web page.
 11. The method of claim 1, whereininstantiating the browser plugin is accomplished by injecting, based onthe action initiated from within the web page, the one or more elementsinto a hidden frame that is separate from the web page.
 12. The methodof claim 1, wherein the browser plugin is a content decryption module.13. The method of claim A, further comprising: employing the client webbrowser to load a web application; employing the web application to geta license for encrypted media content; employing the web application toinstruct a media stack of the client web browser to play the encryptedmedia content; sending the license from the web application to the mediastack; sending the license from the media stack to the contentdecryption module, wherein the media stack and the content decryptionmodule are distinct binaries from each other; and sending encrypted datafrom the media stack to the content decryption module, wherein theencrypted data includes at least a portion of the encrypted mediacontent, and wherein the command to the browser plugin is a command toprovide decrypted data by decrypting the encrypted data.
 14. The methodof claim 1, wherein instantiating the browser plugin includes creating asub-tree of a main document object model, and wherein the sub-tree isinaccessible from the document object model.
 15. The method of claim 14,further comprising destroying the sub-tree.
 16. The method of claim 14,wherein the sub-tree includes a markup tag such that, when rendered,causes the browser plugin to be instantiated.
 17. The method of claim16, wherein instantiating the browser plugin further includes renderingthe sub-tree.
 18. A client device, comprising: a memory component forstoring data; and a processing component that is configured to executedata that enables actions, including: employing a client web browser ofthe client device to instantiate, responsive to an action initiated by aweb rage received by the web browser, a browser plugin for the clientweb browser, the browser plugin being instantiated by the client webbrowser based on one or more elements in a local resource other thanfrom within the web page; employing the client web browser to obtain areference to the browser plugin, the reference to the browser pluginbeing inaccessible from the web page; and providing a command to thebrowser plugin via the reference to the browser plugin.
 19. Amanufacture, including a tangible processor-readable storage mediumhaving processor-executable code encoded therein, which when executed byone or more processors, enables actions, comprising: employing a clientweb browser of a client to instantiate, responsive to an actioninitiated by a web page received by the web browser, a browser pluginfor the client web browser, the browser plugin being instantiated by theclient web browser, not the web page, based on one or more elements in alocal resource that is hidden from the web page; employing the clientweb browser to obtain a reference to the browser plugin the reference tothe browser plugin being inaccessible from the web page; and providing acommand to the browser plugin via the reference to the browser plugin.